1. Field of the Invention
The present invention relates to a keyboard apparatus that can impart a key depression feeling characteristic to a key when the key is depressed.
2. Description of the Related Art
Conventionally, an electronic piano artificially realizes a key depression feeling or a key touch feeling, such as that of an acoustic piano. However, for a keyboard apparatus, such as a portable keyboard, that is desired to be small in size, low in price, and light in weight, it is not easy to provide a mechanism (key touch feeling-imparting mechanism) that realizes the key touch feeling mentioned above, and even when the mechanism can be provided, it is desired to be as simple as possible.
To meet the requirement, Japanese Utility Model Publication (Kokoku) No. S59-39740 has proposed a keyboard apparatus in which a leaf spring having an end thereof bent into the shape of “L” is attached to an instrument body, and which is configured such that an operating element (key) is engaged with the leaf spring at an initial stage of key depression, and is disengaged as the key depression proceeds, whereby the bending of the leaf spring and the disengagement of the bent leaf spring produce a predetermined key depression feeling, with a simplified construction.
However, in the keyboard apparatus disclosed in Japanese Utility Model Publication (Kokoku) No. S59-39740, the reaction force from the depressed key is increased mainly by the bending of the leaf spring located forward of the key except for the reaction force from a key return spring provided at the rear end of the key, and hence the keyboard apparatus leaves room for improvement in obtaining a more definite change in the reaction force from the depressed key (load change). Further, a sudden decrease in the reaction force is produced by only through disengagement of the key from the leaf spring located forward of the key, and hence irrespective of a manner of key depression, such as strong depression or weak depression, a click feeling corresponding to “let-off” is produced always substantially at the same position in the forward stroke of key depression, and hence there remains room for improvement in obtaining a more natural key depression feeling as obtained from the acoustic piano.
When the key touch feeling-imparting mechanism that imparts a predetermined key touch feeling to each key is constructed individually for each key, the key depression feeling tends to vary from one key to another, and hence it is desired that the variations in the key depression feeling should be taken into account in realizing a key touch feeling. Further, it is desired that the key touch feeling-imparting mechanism should be disposed so as not to interfere with essential key function-realizing components, and so as to save space.